Automatic Differential/Motor Speed Compensation

[Ether]

Originally Posted by RSNovi

After turning the robot on the announcers would talk so long that the gyro would start drifting like crazy before the robots started. The reference library takes 5 seconds to calibrate the gyro. I wonder if that could be reduced.

It doesn't take 5 seconds to read the gyro and use that reading as a zero offset.

[RSNovi]

I know reading the gyro doesn't take that long, the calibration routine takes 5 seconds on the 450 gyro. That is when using the WPI class.

When it drifts it really takes off. I reset the gyro at the very beginning, but if it is already drifting it will be off a few degrees in a matter of a few seconds. Ideally I would like to calibrate the gyro in my autonomous init.

[Ether]

Originally Posted by RSNovi

I reset the gyro at the very beginning, but if it is already drifting it will be off a few degrees in a matter of a few seconds.

If you calibrate the gyro when it's cold, it will drift faster when it warms up.

Also make sure you have all vibration sources (like the compressor) turned off when you calibrate.

Or you could try this solution:

http://www.chiefdelphi.com/forums/sh...9&postcount=13
http://www.chiefdelphi.com/forums/sh...8&postcount=17

[mark219]

We used a gyro to drive straight, by taking into account the change in angle and a constant value (a constant much like a P-value in a PID loop).

[RSNovi]

Originally Posted by Ether

If you calibrate the gyro when it's cold, it will drift faster when it warms up.

Also make sure you have all vibration sources (like the compressor) turned off when you calibrate.

Or you could try this solution:

http://www.chiefdelphi.com/forums/sh...9&postcount=13
http://www.chiefdelphi.com/forums/sh...8&postcount=17

I wonder if it would be better to bring the robot up to the course powered up so all of the electronics are warm. Then toggle the power after placement so the calibration is done while everything is somewhat warm.